In a multiple cavity mold used for the manufacture of molded resin parts, the individual mold cavities are connected by supply channels. During the molding process, these channels form elongated and inter-connected molded resin components customarily referred to as "sprues" and "runners." Most modern molding machines automatically sever the molded parts from these sprues and runners at the time the mold is opened. However, it remains necessary to sort the sprues and runners from the molded parts.
This sorting procedure can be and usually has been carried out manually, but it is a tedious, routine, and costly job. Parts separators for carrying out this sorting task are known, but have not been entirely satisfactory because they tend to be rather bulky and often are not adequately reliable in operation. One known type of parts separator employs a conveyor belt upon which the mixture of molded parts, runners and sprues is deposited. At the end of the conveyor belt the molded parts are discharged from the belt by gravity. An upwardly moving conveyor equipped with a multiplicity of fingers or like projections catches the larger sprues and runners and conveys them to a separate location. Examples of such conveyor belt parts separators are disclosed in Suellentrop et al. U.S. Pat. No. 3,651,938 and DeLeon et al. U.S. Pat. No. 3,982,632.
Another known parts separator disclosed in Frazier U.S. Pat No. 4,257,883, comprises a bowl having generally vertical sides; within that bowl, there is a continuously driven rotor of conical configuration with a series of upwardly directed fin-like projections. The periphery of the rotor has a close fit with the inner surface of the bowl. When a mixture of small molded parts, sprues, and runners is deposited on the rotor, the parts fall between the fins to the lower rotor surface but the runners and sprues are held up on the fins. Separation is achieved at two outlets displaced around the periphery of the bowl, one aligned with the lower rotor surface to receive the molded parts and the other permitting egress of the runners and sprues from the higher level defined by the tops of the fins. This rotary parts separator has a tendency to jam, particularly in the area of the discharge port for the runners and sprues. Furthermore, the relatively complex multi-fin rotor of this device presents a distinct economic disadvantage.
In many instances, it is highly desirable to locate a parts separator directly under the molding machine, in position to separate the molded parts from runners and sprues immediately on discharge from the mold. When this is done, the parts separator is not readily accessible and is difficult or impossible to observe. If a jam or other malfunction occurs, the parts separator, the mold, or both may be damaged unless adequate protection is provided.